Earth moving, construction and mining equipment and the like work are often used in rough, off-road terrain. These machines often employ an endless track with track shoes that is better able to propel the machines in such environments over obstacles and uneven terrain, etc. The track chains, which include shoes, are held together by a series of interconnected track links, pins and bushings that are supported on the drive sprocket, idler and support rollers of the machine. As can be imagined, lubrication is necessary to ease the movement of a track roller as the track chain passes over it, allowing the shaft on which the track roller rotates to be fixed while the roller itself rotates. A face seal is often disposed at this interface between the track roller and the shaft, sealing in lubrication while allowing the roller to rotate on the shaft.
Similarly, such equipment may use power trains including a gearbox that is connected to a drive shaft or a wheel axle to power movement to a wheel. The shaft and axle are configured to rotate relative to a housing positioned near them that remains fixed. It is necessary to the ease the movement of the shaft or the axle relative to the housing or other fixed member by providing lubrication in the vicinity of the interface of the shaft or axle and the fixed member. A face seal is often disposed at this interface between the housing or other fixed member and the rotating shaft or rotating axle.
Over time, the face seal assembly experiences wear. Various factors influence wear and there are various types of wear. For example, radial wear and/or asymmetric wear may occur. With current seal face geometry, retarding radial wear may increase asymmetric wear and vice, versa. Either type of wear, radial wear or asymmetric wear, will eventually cause the face seal to no longer effectively seal the desired lubricant in the lubricating cavity formed by the rotating component and the fixed component. This can cause downtime for the machine and presents a cost to the end user who then needs to replace the face seal.
Accordingly, it is desirable to develop a face seal sealing surface that breaks the radial wear versus asymmetric wear trade-off or compromise.